Wooden Framing

A steel structure is dense and immensely strong, but steel is also hard to work with. The struts in The Dwelling are round so they are resistant to torque. Otherwise, force down on the top of the structure could turn into the top rotating, and torquing (twisting) all of the vertical struts.

The flanges at each connector give us bolt-points for the next step of our build: the wooden frame that the inner and outer surfaces of the structure attach to. Each face of the structure will have a wooden frame sitting inside the metal one. This wooden frame does a bunch of things.

First, depending on how thick it is, it raises the inner and outer surfaces away from the metal frame. The connectors are 2.375” and 2.5” thick; if you just attach 3/4” plywood directly to the flanges, then the plane of the plywood will be below the metal frame. Since we are going to stick LED strips on the edge of the metal frame (and they are 1.25” thick), this would look bad: you’d see the shimmering Alucobond, then a steel connector/strut, with LEDs obviously sitting on top of it. What we want to do is raise the Alucbond high enough that its surface is *just* below the LED strip, so the LED strip sticks out by 1/8” or so, and the edge of the Alucobond panel is almost perfectly flush. For the upper panels, we might need to raise things a bit higher so the panels can rest on the structure itself, rather than just the flanges.

Similarly, on the inside, we want to raise the plane of the covering so that it will completely cover the struts and connectors. In the best case, we’ll have two planes that intersect at a perfect join (we’ll be getting to the inner surface in later posts, when we get there; there are a bunch of very cool ideas in play, such as thermally responsive paint).

Second, the frame needs to attach to the bolt points, so that it is firmly connected to the metal frame.

Finally, we need to be able to mount the inner and outer surfaces on the wooden frame. Right now, we’re planning on a seamless exterior: we’re going to glue Alucobond to 3/4” plywood sheets, then screw the sheets to the frame. The screws will penetrate the plywood about 1/2” into the 3/4”. The inner surfaces will then sit on top of these screws, hiding them.

Mike Briganti is an old friend who used to do lots of wood finish work and is now a supervisor for construction projects around the city. He helped us a lot when we built the Mitford machine (a coffin lid is a complex 3D shape!) and is helping out again for The Dwelling. He picked me up at 8AM so we could head to Lowe’s. I’d put an order at 8AM yesterday, but they hadn’t filled it, so cancelled it and we went around and picked up everything we needed to make a template for the wooden frame. 4 8ft 2x4s, 2 8ft 4x4s, two sheets of 3/4” plywood (lower panels) and one sheet of 1 1/8” plywood (upper panels). 3/4” is fine for walls, but you want 1 1/8” for floors (e.g., the top of the structure).

We brought the stuff to the Box Shop and got working. We started with the 2x4s since they are a lot faster to work with, and ultimately decided on a design that uses 3x3s. So we take a 4x4 and cut it down to be 3x3. We then cut a notch out of the corner of the inside face, so that there is 1 1/4” of wood on top of the flange on the outside (it raises the plane 1 1/4” up from the flange, such that 3/4” plywood plus 4mm Alucobond will be just below the LED level). Drill a hole where the flange hole is, use a carriage bolt, and voila! You can see the notches on the bottom framing piece if you look closely at the corners.

Tomorrow I’m going to finish the 3x3 frame and cut the plywood for the face. Mike pointed out that we can then screw the whole thing together: it can just be a rigid wooden frame we slot into the structure (rather than having to assemble it on playa).

One big advantage to doing this first instance with Mike is now it’s clear exactly what tools I'll need. For example, the table saw I was using can only cut about 2 5/8”, so cutting notches out of 3” material is hard. Having a little hand saw to do the last bit is very helpful.

Once I’ve sized the plywood panel, then we can cut the Alucobond lower panels. This is the point at which The Dwelling is going to start showing its beauty.


Phil